21544030840 has 32 divisors (see below), whose sum is σ = 51025338000. Its totient is φ = 8164053504.

The previous prime is 21544030817. The next prime is 21544030841. The reversal of 21544030840 is 4803044512.

It is a super-2 number, since 2×21544030840² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21544030841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14172945 + ... + 14174464.

Almost surely, 2^21544030840 is an apocalyptic number.

21544030840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21544030840 is an abundant number, since it is smaller than the sum of its proper divisors (29481307160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21544030840 is a wasteful number, since it uses less digits than its factorization.

21544030840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28347439 (or 28347435 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 31.

The spelling of 21544030840 in words is "twenty-one billion, five hundred forty-four million, thirty thousand, eight hundred forty".